The invention relates to a ventilation device with a rectangular frame containing a shut-off element, such as known in practice.
Both in modern building and in renovation projects, in particular when double glazing is used, different thicknesses of glass are used, and in the state of the art a suitable device must be designed for each thickness of glass. This means that a large number of ready devices of different types, suitable for different thicknesses of glass panels, always have to be kept in stock, which means, of course, a considerable investment, also in storage space.